RICHTEK RT9176

RT9176
1.5A Fixed and Adjustable Low Dropout Positive Voltage
Regulators
General Description
Features
The RT9176 series of high performance positive voltage
regulators is designed for applications requiring low dropout
performance at fully rated current. Additionally, the RT9176
series provides excellent regulation over variations in line
and load. Outstanding features include low dropout
performance at rated current, fast transient response,
internal current-limiting, and thermal-shutdown protection
of the output device. The RT9176 series of three terminal
regulators offers fixed and adjustable voltage options
available in space-saving SOT-223, TO-252, and TO-263
packages.
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Applications
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Ordering Information
RT9176Package Type
G : SOT-223
L: TO-252
M : TO-263
Operating Temperature Range
P : Pb Free with Commercial Standard
G : Green (Halogen Free with Commercial Standard)
Output Voltage
Default : Adjustable
15 : 1.5V
18 : 1.8V
25 : 2.5V
28 : 2.85V
33 : 3.3V
35 : 3.5V
Low Dropout Performance, 1.5V Max.
Full Current Rating Over Line and Temperature
Fast Transient Response
± 2% Output Voltage Accuracy
1.5V, 1.8V, 2.5V, 2.85V, 3.3V, and 3.5V Fixed and
Adjustable Output Voltage
SOT-223, TO-252, and TO-263 Packages
RoHS Compliant and 100% Lead (Pb)-Free
z
Active SCSI Termination
Low Voltage Microcontrollers
Switching Power Supply Post-Regulator
Pin ConFigurations
(TOP VIEW)
3
VIN
2
VOUT (TAB)
1
ADJ/GND
SOT-223
VIN
2
VOUT (TAB)
1
Note :
RichTek Pb-free and Green products are :
3
ADJ/GND
TO-252
`RoHS compliant and compatible with the current requirements of IPC/JEDEC J-STD-020.
`Suitable for use in SnPb or Pb-free soldering processes.
3
VIN
`100%matte tin (Sn) plating.
2
VOUT (TAB)
1
ADJ/GND
TO-263
DS9176-11 March 2007
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1
RT9176
Typical Application Circuit
RT9176
VIN
VIN = 5V
VOUT = 3.45V
VOUT
ADJ
C1
10uF
IADJ
R1
133
1%
+
+
VREF
C2
10uF
R2
232
1%
Tantalum
V OUT = V REF (1+
R2
R1
) + I ADJ R 2
(1) C1 needed if device is far from filter capacitors.
(2) C2 required for stability.
Figure 1. Adjustable Voltage Regulator
VIN
VIN = 5V
RT9176-33
VOUT
VOUT
3.3V
GND
+
+
C1
10uF
IQ
C2
10uF
Tantalum
(1) C1 needed if device is far from filter capacitors.
(2) C2 required for stability.
Figure 2. Active SCSI Bus Terminator
RT9176-28
VIN
VOUT
18 - 27 Lines
GND
+
+
10uF
22uF
IQ
Figure 3. Fixed Voltage Regulator
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DS9176-11 March 2007
RT9176
Function Block Diagram
VIN
S.O.A.
Current
Limiting
Amplifier
LIMIT
VOUT
SENSE
Thermal Overload
Voltage
Regulation
Amplifer
VREF
ADJ/GND
Functional Pin Description
Pin Name
Pin Function
ADJ/GND
Adjust Output Voltage or GND
VOUT
Output Voltage
VIN
Power Input
DS9176-11 March 2007
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3
RT9176
Absolute Maximum Ratings
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(Note 1)
Supply Input Voltage -------------------------------------------------------------------------------------------------- 15V
Power Dissipation, PD @ TA = 25°C
SOT-223 ----------------------------------------------------------------------------------------------------------------- 0.740W
TO-252 ------------------------------------------------------------------------------------------------------------------- 1.471W
TO-263 ------------------------------------------------------------------------------------------------------------------- 2.222W
Package Thermal Resistance (Note 6)
SOT-223, θJA ------------------------------------------------------------------------------------------------------------ 135°C/W
SOT-223, θJC ----------------------------------------------------------------------------------------------------------- 19°C/W
TO-252, θJA ------------------------------------------------------------------------------------------------------------- 68° C/W
TO-252, θJC ------------------------------------------------------------------------------------------------------------- 7.5° C/W
TO-263, θJA ------------------------------------------------------------------------------------------------------------- 45° C/W
TO-263, θJC ------------------------------------------------------------------------------------------------------------- 7.8° C/W
Lead Temperature (Soldering, 10 sec.) --------------------------------------------------------------------------- 260° C
Junction Temperature ------------------------------------------------------------------------------------------------- 150°C
Storage Temperature Range ---------------------------------------------------------------------------------------- −65°C to 150°C
ESD Susceptibility (Note 2)
HBM (Human Body Mode) ------------------------------------------------------------------------------------------ 8kV
MM (Machine Mode) -------------------------------------------------------------------------------------------------- 750V
Recommended Operating Conditions
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(Note 3)
Supply Input Voltage -------------------------------------------------------------------------------------------------- 3V to 12V
Junction Temperature Range ---------------------------------------------------------------------------------------- −40°C to 125°C
Electrical Characteristics
(TA = 25° C, unless otherwise specified)
Parameter
Symbol
Test Conditions
IOUT = 10mA, (VIN−VOUT) = 2V,
Reference Voltage
(Note 4)
RT9176
VREF
RT9176-15
RT9176-18
RT9176-25
Output Voltage
(Note 4)
VOUT
RT9176-28
RT9176-33
RT9176-35
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Min
Typ
Max
Units
1.243 1.256 1.281
V
10mA < IOUT < 1.5A,
1.5V < VIN-VOUT < 10V
1.231 1.256 1.294
V
IOUT = 10mA, VIN = 3.3V, TJ = 25°C
1.485
1.5
1.53
0 < IOUT < 1.5A, 3.3V < VIN < 10V
1.470
1.5
1.55
IOUT = 10mA, VIN = 3.3V, TJ = 25°C
1.797 1.815
1.85
0 < IOUT < 1.5A, 3.3V < VIN < 10V
1.779 1.815
1.87
IOUT = 10mA, VIN = 4.0V, TJ = 25°C
2.460 2.500 2.544
0 < IOUT < 1.5A, 4.0V < VIN < 10V
2.450 2.500 2.550
IOUT= 10mA, VIN= 4.25V, TJ = 25°C
2.822 2.850 2.910
0 < IOUT < 1.5A, 4.25V < VIN < 10V
2.793 2.850 2.936
TA = 25°C
V
IOUT = 10mA, VIN = 4.75V, TJ = 25°C 3.267 3.300 3.365
0 < IOUT< 1.5A, 4.75V < VIN < 10V
3.234 3.300 3.400
IOUT = 10mA, VIN= 5V, TJ = 25°C
3.465 3.500 3.570
0 < IOUT < 1.5A, 5.0V < VIN < 10V
3.430 3.500 3.605
DS9176-11 March 2007
RT9176
Parameter
Symbol
Test Conditions
Min Typ Max Units
RT9176
IOUT = 10mA,
1.5V ≤ VIN−V OUT ≤ 10V
--
0.1
0.3
%
RT9176-15
I OUT = 0mA, 3.3V ≤ VIN ≤ 15V
--
1
6
mV
I OUT = 0mA, 3.3V ≤ VIN ≤ 15V
--
1
6
mV
I OUT = 0mA, 4.0V ≤ VIN ≤ 15V
--
1
6
mV
RT9176-28
I OUT = 0mA, 4.25V ≤ VIN ≤ 15V
--
1
6
mV
RT9176-33
I OUT = 0mA, 4.75V ≤ VIN ≤ 15V
--
1
6
mV
RT9176-35
I OUT = 0mA, 5.0V ≤ VIN ≤ 15V
--
1
6
mV
RT9176
(VIN−VOUT) = 3V, 0mA ≤ I OUT ≤ 1.5A
--
0.2
0.4
%
RT9176-15
VIN = 3.3V, 0 ≤ I OUT ≤ 1.5A
--
1
10
mV
RT9176-18
VIN = 3.3V, 0 ≤ I OUT ≤ 1.5A
--
1
10
mV
VIN = 4.0V, 0 ≤ I OUT ≤ 1.5A
--
1
10
mV
RT9176-28
VIN = 4.25V, 0 ≤ I OUT ≤ 1.5A
--
1
10
mV
RT9176-33
VIN = 4.75V, 0 ≤ I OUT ≤ 1.5A
--
1
12
mV
RT9176-35
VIN = 5.0V, 0 ≤ I OUT ≤ 1.5A
--
1
15
mV
I OUT = 500mA
--
1.15 1.25
V
I OUT = 1.5A
--
1.3
1.5
V
1.5
1.75
--
A
(VIN−VOUT) = 2V
--
5
10
mA
IQ
VIN = 5V
--
5
10
mA
Ripple Rejection
PSRR
fRIPPLE = 120Hz ,
(VIN − VOUT) = 2V, VRIPPLE = 1VP-P
--
72
--
dB
Adjust Pin Current
IADJ
--
65
120
μA
Adjust Pin Current Change
ΔIADJ
--
0.2
5
μA
Line Regulation
(Note 4)
Load Regulation
(Note 4)
Dropout Voltage
RT9176-18
RT9176-25
RT9176-25
(Note 5)
Current Limit
ΔVLINE
ΔVLOAD
VDROP
ILIM
Minimum Load Current RT9176
Quiescent Current
RT9176-XX
VIN = 5V
10mA ≤ IOUT ≤ 1.5A, VIN = 5V
Note 1. Stresses listed as the above “Absolute Maximum Ratings” may cause permanent damage to the device. These are for
stress ratings. Functional operation of the device at these or any other conditions beyond those indicated in the
operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended
periods may remain possibility to affect device reliability.
Note 2. Devices are ESD sensitive. Handling precaution recommended.
Note 3. The device is not guaranteed to function outside its operating conditions.
Note 4. Low duty cycle pulse testing with Kelvin connections.
Note 5. The dropout voltage is defined as VIN -VOUT, which is measured when VOUT is VOUT(NORMAL) − 100mV.
Note 6. θJA is measured in the natural convection at T A = 25°C on a low effective thermal conductivity test board of
JEDEC 51-3 thermal measurement standard. The pad size is 6mm2 on SOT-223 packages, 100mm2 on TO-252
packages, 125mm2 on TO-263 packages.
DS9176-11 March 2007
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RT9176
Typical Operating Characteristics
Output Voltage vs. Temperature
Reference Voltage vs. Temperature
1.27
3.4
Output Voltage (V)
3
2.6
VOUT = 2.5V
2.2
VIN = 5V
CIN = 10uF Electrolytic
CO = 10uF Tantalum
RL = ∞
1.8
VOUT = 1.5V
1.4
Reference Voltage (V)
VOUT = 3.3V
1.26
1.25
VIN = 5V
CIN = 10uF Electrolytic
CO = 10uF Tantalum
R1 = R2 = 100Ω
RL = ∞
1.24
1.23
-50
-25
0
25
50
75
100
125
-50
Temperature (° C)
0
50
75
100
125
Quiescent Current vs. Temperature
ADJ Pin Current vs. Temperature
70
60
VIN = 5V
CIN = 10uF Electrolytic
CO = 10uF Tantalum
R1 = R2 = 100Ω
RL = ∞
50
Quiescent Current (mA)
7
6
5
VOUT = 2.5V
4
3
2
VIN = 5V
CIN = 10uF Electrolytic
CO = 10uF Tantalum
RL = ∞
1
40
0
-50
-25
0
25
50
75
100
125
-50
-25
0
Temperature (° C)
25
50
75
Temperature(° C)
100
125
Current Limit vs. Temperature
Current Limit vs. Input Voltage
2
3
2.5
1.9
VOUT = 2.5V, RL = 1Ω
2
1.5
1
Current Limit (A)1
Current Limit (A)
25
Temperature (° C)
80
ADJ Pin Current (uA)
-25
1.8
VOUT = 2.5V, RL = 1Ω
1.7
VIN = 5V
CIN = 10uF Electrolytic
CO = 10uF Tantalum
1.6
0.5
CIN = 10uF Electrolytic
CO = 10uF Tantalum
0
2
4
6
8
10
Input Voltage (V)
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12
14
1.5
-50
-25
0
25
50
75
100
125
Temperature (° C)
DS9176-11 March 2007
RT9176
Current Limit
Dropout Voltage vs. Load Current
3.5
VOUT = 2.5V
-40°C
3
1.2
25°C
1.1
1.0
125°C
Current Limit (A)
Dropout Voltage (V) 1
1.3
CIN = 10uF Electrolytic
CO = 10uF Tantalum
0
0.3
0.6
0.9
1.2
2
1.5
1
VIN = 5V, VOUT = 2.5V
CIN = 10uF Electrolytic
CO = 10uF Tantalum
RL = 1Ω
0.5
0.9
0.8
2.5
0
Time (2.5ms/Div)
1.5
Load Current (A)
VOUT = 1.5V
CO = 10uF Tantalum
ILOAD = 100mA
20
10
0
Line Transient Response
Output Voltage
Deviation (mV)
Output Voltage
Deviation (mV)
Line Transient Response
30
Input Voltage
Deviation (V)
7
6
5
30
20
0
7
6
5
Time (10us/Div)
Time (10us/Div)
Line Transient Response
Load Transient Response
40
30
VOUT = 3.3V
CO = 10uF Tantalum
ILOAD = 100mA
20
0
Output Voltage
Deviation (mV)
Input Voltage
Deviation (V)
Output Voltage
Deviation (mV)
VOUT = 2.5V
CO = 10uF Tantalum
ILOAD = 100mA
-20
-10
7
6
5
Time (10us/Div)
DS9176-11 March 2007
300
200
VIN = 3.3V, VOUT = 1.5V
CIN = CO = 10uF Tantalum
Preload = 0.1A
100
0
-100
Load Current (A)
-20
Input Voltage
Deviation (V)
40
1
0.5
0
Time (10us/Div)
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RT9176
200
100
VIN = 3.3V, VOUT = 1.5V
CIN = CO = 10uF Tantalum
Preload = 0.1A
0
Load Transient Response
300
Output Voltage
Deviation (mV)
Output Voltage
Deviation (mV)
Load Transient Response
300
100
2
1
0
0
1
0.5
0
Time (10us/Div)
Time (10us/Div)
200
100
VIN = 5V, VOUT = 2.5V
CIN = CO = 10uF Tantalum
Preload = 0.1A
0
Load Current (A)
Load Current (A)
-100
Load Transient Response
300
Output Voltage
Deviation (mV)
Output Voltage
Deviation (mV)
Load Transient Response
300
VIN = 5V, VOUT = 2.5V
CIN = CO = 10uF Tantalum
Preload = 0.1A
-100
Load Current (A)
Load Current (A)
-100
200
2
1
0
Time (10us/Div)
VVININ == 5V,
5V, VVOUT
3.3V
OUT == 3.3V
200 CCININ==CCOO==10uF
10uFTantalum
Tantalum
Preload
Preload==0.1A
0.1A
100
0
-100
1
0.5
0
Time (10us/Div)
Output Voltage
Deviation (mV)
Load Transient Response
300
200
100
VIN = 5V, VOUT = 3.3V
CIN = CO = 10uF Tantalum
Preload = 0.1A
0
Load Current (A)
-100
2
1
0
Time (10us/Div)
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DS9176-11 March 2007
RT9176
Application Information
Output voltage adjustment
Output Capacitor
Like most regulators, the RT9176 regulates the output by
comparing the output voltage to an internally generated
reference voltage. On the adjustable version as shown in
Figure 4, the VREF is available externally as 1.25V between
VOUT and ADJ. The voltage ratio formed by R1 and R2
should be set to conduct 10mA (minimum output load).
The output voltage is given by the following equation:
RT9176 requires a capacitor from VOUT to GND to provide
) + IADJ R2
On fixed versions of RT9176, the voltage divider is provided
internally.
VIN
VIN
Region of Stable COUT ESR vs. Load Current
RT9176
VOUT
R1
COUT = 100uF
10uF
+
CADJ
Instable
+
+
VREF
IADJ
65uA
10
VOUT
ADJ
10uF
The output capacitor does not have a theoretical upper
limit and increasing its value will increase stability.
COUT = 100μF or more is typical for high current regulator
design.
R2
C OUT ESR (Ω)
VOUT = VREF
R2
(1+
R1
compensation feedback to the internal gain stage. This is
to ensure stability at the output terminal. Typically, 10μF
tantalum or 50μF aluminum electrolytic is sufficient and
please takes the notice of output capacitor ESR range
(Figure 5).
COUT = 10uF
1
Stable
0.1
Figure 4. Basic Adjustable Regulator
Instable
Input Bypass Capacitor
An input capacitor is recommended. A 10μF tantalum on
the input is a suitable input bypassing for almost all
applications.
0.01
0
0.2
0.4
0.6
0.8
1
Load Current (A)
Figure 5
Adjust Terminal Bypass Capacitor
The adjust terminal can be bypassed to ground with a
bypass capacitor (CADJ) to improve ripple rejection. This
bypass capacitor prevents ripple from being amplified as
the output voltage is increased. At any ripple frequency,
the impedance of the CADJ should be less than R1 to
prevent the ripple from being amplified:
(2p * fRIPPLE * CADJ) < R1
The R1 is the resistor between the output and the adjust
pin. Its value is normally in the range of 100-200Ω. For
example, with R1 = 124Ω and fRIPPLE = 120Hz, the CADJ
should be > 11μF.
DS9176-11 March 2007
Load Regulation
When the adjustable regulator is used (Figure 6), the best
load regulation is accomplished when the top of the resistor
divider (R1) is connected directly to the output pin of the
RT9176. When so connected, RP is not multiplied by the
divider ratio. For Fixed output version, the top of R1 is
internally connected to the output and ground pins can be
connected to low side of the load.
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RT9176
VIN
RT9176
VIN
VOUT
GND
RP Parasitic
Line Resistance
R1
(Connect R1 to VOUT or case)
R2
RL
Connect R2 to load
Figure 6. Best Load Regulation Using Adjustable Output
Regulator
Thermal Protection
RT9176 has thermal protection which limits junction
temperature to 150°C. However, device functionality is only
guaranteed to a maximum junction temperature of +125°C.
The power dissipation and junction temperature for RT9176
are given by
PD = (VIN - VOUT) x IOUT
TJUNCTION = TAMBIENT + (PD x θJA)
Note: TJUNCTION must not exceed 125° C
Current Limit Protection
RT9176 is protected against overload conditions. Current
protection is triggered at typically 1.75A.
Thermal Consideration
The RT9176 series contain thermal limiting circuitry
designed to protect itself from over-temperature conditions.
Even for normal load conditions, maximum junction
temperature ratings must not be exceeded. As mention
in thermal protection section, we need to consider all
sources of thermal resistance between junction and
ambient. It includes junction-to-case, case-to-heat-sink
interface, and heat sink thermal resistance itself.
Junction-to-case thermal resistance is specified from the
IC junction to the bottom of the case directly below the
die. Proper mounting is required to ensure the best
possible thermal flow from this area of the package to the
heat sink. The case of all devices in this series is
electrically connected to the output. Therefore, if the case
of the device must be electrically isolated, a thermally
conductive spacer is recommended.
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DS9176-11 March 2007
RT9176
Outline Dimension
D
D1
H
C
B
L
e
L1
e
A
A1
b
Symbol
Dimensions In Millimeters
Dimensions In Inches
Min
Max
Min
Max
A
1.450
1.803
0.057
0.071
A1
0.020
0.100
0.0008
0.0047
b
0.610
0.787
0.024
0.031
B
3.302
3.708
0.130
0.146
C
6.706
7.290
0.264
0.287
D
6.299
6.706
0.248
0.264
D1
2.896
3.150
0.114
0.124
e
2.261
2.362
0.089
0.093
H
0.229
0.330
0.009
0.013
L
1.550
1.950
0.061
0.077
L1
0.800
1.100
0.009
0.013
3-Lead SOT-223 Surface Mount Package
DS9176-11 March 2007
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11
RT9176
D
U
C
D1
R
B
T
V
E
S
L1
L3
b1
b
L2
e
b2
A
Symbol
Dimensions In Millimeters
Dimensions In Inches
Min
Max
Min
Max
A
2.184
2.388
0.086
0.094
B
0.889
2.032
0.035
0.080
b
0.508
0.889
0.020
0.035
b1
1.016 Ref.
0.040 Ref.
b2
0.457
0.584
0.018
0.023
C
0.457
0.584
0.018
0.023
D
6.350
6.731
0.250
0.265
D1
5.207
5.461
0.205
0.215
E
5.334
6.223
0.210
0.245
e
2.108
2.438
0.083
0.096
L1
9.398
10.414
0.370
0.410
L2
L3
0.508 Ref.
0.635
1.016
0.020 Ref.
0.025
0.040
U
3.810 Ref.
0.150 Ref.
V
3.048 Ref.
0.120 Ref.
R
0.200
0.850
0.008
0.033
S
2.500
3.400
0.098
0.134
T
0.500
0.850
0.020
0.033
3-Lead TO-252 Surface Mount Package
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DS9176-11 March 2007
RT9176
C
D
U
B
V
E
L1
b1
L2
e
b2
b
A
Symbol
Dimensions In Millimeters
Dimensions In Inches
Min
Max
Min
Max
A
4.064
4.826
0.160
0.190
B
1.143
1.676
0.045
0.066
b
0.660
0.914
0.026
0.036
b1
1.143
1.397
0.045
0.055
b2
0.305
0.584
0.012
0.023
C
1.143
1.397
0.045
0.055
D
9.652
10.668
0.380
0.420
E
8.128
9.652
0.320
0.380
e
2.286
2.794
0.090
0.110
L1
14.605
15.875
0.575
0.625
L2
2.286
2.794
0.090
0.110
U
6.223 Ref.
0.245 Ref.
V
7.620 Ref.
0.300 Ref.
3-Lead TO- 263 Surface Mount Package
Richtek Technology Corporation
Richtek Technology Corporation
Headquarter
Taipei Office (Marketing)
5F, No. 20, Taiyuen Street, Chupei City
8F, No. 137, Lane 235, Paochiao Road, Hsintien City
Hsinchu, Taiwan, R.O.C.
Taipei County, Taiwan, R.O.C.
Tel: (8863)5526789 Fax: (8863)5526611
Tel: (8862)89191466 Fax: (8862)89191465
Email: [email protected]
DS9176-11 March 2007
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13